Restructuring Charges (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 1,416	$ 2,029	$ 1,530
Restructuring Costs	4,471	18,772
Payments for Restructuring	(5,077)	(18,256)
Restructuring Reserve, Accrual Adjustment	(7)	(17)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	677	915	53
Restructuring Costs	4,311	15,983
Payments for Restructuring	(4,549)	(15,104)
Restructuring Reserve, Accrual Adjustment	0	(17)
Special Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	739	1,114	1,477
Restructuring Costs	0	0
Payments for Restructuring	(368)	(363)
Restructuring Reserve, Accrual Adjustment	(7)	0
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0	0	$ 0
Restructuring Costs	160	2,789
Payments for Restructuring	(160)	(2,789)
Restructuring Reserve, Accrual Adjustment	$ 0	$ 0